| 2001 | 2002 | 2005 | 2007 | 2009 | 2011 | ||
| A+ | 0 | 3 | 2 | 1 | 0 | 0 | |
| A | 15 | 5 | 3 | 4 | 7 | 2 | |
| A− | 5 | 12 | 5 | 1 | 0 | 5 | |
| B+ | 4 | 9 | 5 | 2 | 2 | 1 | |
| B | 16 | 10 | 3 | 0 | 5 | 5 | |
| B− | 4 | 4 | 3 | 1 | 2 | 3 | |
| C+ | 8 | 4 | 3 | 1 | 5 | 1 | |
| C | 9 | 3 | 3 | 2 | 0 | 6 | |
| C− | 2 | 6 | 0 | 0 | 2 | 0 | |
| D+ | 3 | 4 | 0 | 1 | 2 | 0 | |
| D | 3 | 0 | 1 | 1 | 0 | 2 | |
| D− | 2 | 1 | 0 | 0 | 0 | 1 | |
| E | 0 | 1 | 0 | 0 | 0 | 0 | |
| total | 71 | 62 | 28 | 14 | 25 | 26 | |
| dropped | 12 | 5 | 5 | 6 | 4 | 6 | |
| helped by EC | 5 | 6 | 11 | 5 | 2 | 2 | |
